One of the most consistent criticisms of demonstrations like this, in addition to the assumption that aiki is fake, is that the responses of the uke do not match the physical output of the tori. They are used to large, external movements being required to throw someone. The very foundation of internal martial arts, Aiki Jujutsu being one of them, is that power is generated in a subtle manner that is imperceptible to the untrained eye. There's nothing esoteric about it. It's not based on magic or anything mystical like chi. It's just a different way of transmitting force through the body (and into another person through physical touch) that is generated through cohesive body movement rather than segregating a limb from the rest of the core. I'll write more articles on the subject in greater detail, but here I'd like to focus on the uke.
This is not the case. Demonstrations of techniques are just that: demonstrations. They are meant to showcase a specific technique, skill or principle. The uke is compliant in that they are adhering to the parameters of the demonstration. It's important to note that they should still give solid structure and resistance, as many techniques do not work without it. In my dojo, we say "limp noodles are useless." However, during the demonstration they are not engaged in a live sparring or pressure testing. In sparring there are no clearly defined uke and tori roles. In demonstrations, the uke are feeding the tori specific attacks and responding to the technique being performed without countering.
Ukemi 受け身 is an art unto itself. In a literal sense, it means "receiving body or self." It's a set of techniques that allow you to receive a technique safely without enduring bodily harm. This includes break falling, rolling, etc. In my opinion, these are the most important techniques anyone can learn as the odds of you becoming a victim of a violent assault and having to use your physical training are a lot less than slipping and falling as you get older. In arts with a heavy emphasis on throws and takedowns, ukemi is an essential skill to practice the art at all. Without having good ukemi, your training partners cannot practice their techniques on you because it would be unsafe.
In the aiki arts specifically, ukemi is a form of sensitivity training. By receiving techniques, you begin to develop the sensitivity to recognize different vectors of force being applied and perceive the subtleties not observed by those simply watching the demonstration. This is one reason we say "feeling is believing." Without truly feeling what is going on in a given technique, you cannot begin to understand it. Furthermore, your instructor is actually teaching your body how to move when they perform the technique on you so that you can replicate it in your own practice.
In actuality, many times you see a roll or flip from uke would actually be a face plant or awkward barrel roll from an untrained partner. Neither one of those options puts you in an advantageous position, but by rolling through following the momentum of the technique you are able to get ahead of it and recover. That's all.
As I said, it's not about theatrics. It's not about making the tori look good, and it's not about being cooperative. Ukemi is a skillset that allows techniques to be practiced at full speed without risk of injury, and allowing the uke to recover to an advantageous position. Compare this with the responses of an untrained partner as in the video below:
So are the flips and rolls real? Yes, in the sense that they are uke's conscious response to receiving the technique, but no in the fact that they are not how the average person would react. Nobody is being flipped from a "flick of the wrist." As I said, and as shown in the video above, the average person when receiving a throw or technique that would normally cause an uke to roll or flip would actually result in either a face plant or an awkward fall. Like anything else in the martial arts, context is everything. Once you understand why something is done the way it is, you are able to see the value of it.